The Mesa 3D Graphics Library

Mesa 9.1 Release Notes / February 22, 2013

Mesa 9.1 is a new development release.
People who are concerned with stability and reliability should stick
with a previous release or wait for Mesa 9.1.1.

Mesa 9.1 implements the OpenGL 3.1 API, but the version reported by
glGetString(GL_VERSION) or glGetIntegerv(GL_MAJOR_VERSION) /
glGetIntegerv(GL_MINOR_VERSION) depends on the particular driver being used.
Some drivers don't support all the features required in OpenGL 3.1. OpenGL
3.1 is only available if requested at context creation
because GL_ARB_compatibility is not supported.